i dont think any gambler will intentionally want their kid to see them doing it. kids learn so fast and when they see their parent doing it they also want to try. its good to take caution and be very careful sometimes these kids might be watching their parents without them knowing and then they go to start practising behind them. one thing about children is that the like to practise what they see and if they see it constantly, it gives them confidence to want to try it.
That's why it's better not to show it to children, because when children see something new in their eyes, curiosity will immediately exist to find out about it, and they won't realize it until they get what they want. So it's really right not to show it only in gambling.
Of course, there are other things that will not bring them good things, and whatever things are not good, let them understand or teach them correctly that it is not good for young people like them to do; that's just the way it is easy to do if we care about them.